package com.xxxx.server.config;

import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.xxxx.server.utils.JwtTokenUtil;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.simp.config.ChannelRegistration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.messaging.simp.stomp.StompCommand;
import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
import org.springframework.messaging.support.ChannelInterceptor;
import org.springframework.messaging.support.MessageHeaderAccessor;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;

import javax.annotation.Resource;

@Configuration
@EnableWebSocketMessageBroker//启用websocket
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Value("${jwt.tokenHead}")
    private String tokenHead;
    @Resource
    private JwtTokenUtil jwtTokenUtil;
    @Resource
    private UserDetailsService userDetailsService;
    /**
     * 添加这个Endpoint端点，这样在网页可以通过websocket连接上服务
     * 也就是我们配置websocket的服务地址，并且可以指定是否使用socketJS
     *
     * @param registry
     */
    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        //将ws/ep路径注册为stomp的端点，用户连接了这个端点就可以进行websocket通讯，支持socketJS
        registry.addEndpoint("/ws/ep")
                //：允许跨域
                .setAllowedOrigins("*")
                //支持socketJS访问
                .withSockJS();
    }

    /**
     * 输入参数通道设置
     *
     * @param registration
     */
    /*
    因为我们使用了SpringSecurity，我们需要通过输入管道将token传进来做相应的校验，否则无法进行websocket
    而且security配置也需要放心webSocket
     */
    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {
        registration.interceptors(new ChannelInterceptor() {
            @Override
            public Message<?> preSend(Message<?> message, MessageChannel channel) {
                StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
                //判断是否为连接，如果是，需要获取token，并且设置用户对象
                if (StompCommand.CONNECT.equals(accessor.getCommand())) {
                    String token = accessor.getFirstNativeHeader("Auth-Token");
                    if (StringUtils.isNotBlank(token)) {
                        String authToken = token.substring(tokenHead.length());
                        //从token中获取用户名
                        String username = jwtTokenUtil.getUserNameFormToken(authToken);
                        //token中存在用户名
                        if (StringUtils.isNotBlank(username)) {
                            //登录
                            UserDetails userDetails = userDetailsService.loadUserByUsername(username);
                            //验证token是否有效，重新设置用户对象
                            if (jwtTokenUtil.validateToken(authToken, userDetails)) {
                                UsernamePasswordAuthenticationToken authenticationToken =
                                        new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());
                                SecurityContextHolder.getContext().setAuthentication(authenticationToken);
                                accessor.setUser(authenticationToken);
                            }
                        }
                    }
                }
                return message;
            }
        });

    }

    /**
     * 功能描述: <br>
     * 〈配置消息代理〉
     *
     */
    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        //配置代理域，可以配置多个，配置代理目的地前缀为/queue,可以在配置域上向客户端推送消息
        registry.enableSimpleBroker("/queue");
    }
}
